<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>
<body>
  <div id="test"></div>

  <script type="text/javascript" src="../js/react.development.js"></script>
  <script type="text/javascript" src="../js/react-dom.development.js"></script>
  <script type="text/javascript" src="../js/babel.min.js"></script>

  <script type="text/babel">
  class Demo extends React.Component {
    /*
    React.createRef调用后可以返回一个容器 该容器可以存储被ref 所标识的节点
    */
    myRef = React.createRef()
    myRef2 = React.createRef()

    //展示左侧输入框的数据
    showData = ()=>{
      alert(this.myRef.current.value);
    }
    //展示右侧输入框的数据
    showData2 = ()=>{
      alert(this.myRef2.current.value);
      
      //函数体
    }
    render() {
      return (
        <div>
        <input  ref={this.myRef} type="text" placeholder="点击按钮提示数据"/>&nbsp;  
        <button  onClick={this.showData}>点我提示左侧的数据</button>&nbsp;
        <input  onBlur={this.showData2} ref={this.myRef2} type="text" placeholder="失去焦点提示数据"/>&nbsp;  

        </div>
      )
    }
  }
  //渲染组件到页面
  ReactDOM.render(<Demo a="1" b="2"/>,document.getElementById('test'))
  </script>
</body>
</html>